We have long touted the benefits and general awesomeness of bike sharing. Not only are bikes a cheap and easy way to zip around cities, but swapping a gas-guzzling car for pedal-powered two-wheeler is one of the easiest ways to curb carbon emissions and make our world a greener place. But now we have an even better reason to promote bike sharing: they actually save lives. A new study published by the British Medical Journal looked at Barcelona’s bike sharing program and found that the benefits of bike shares contributed to 12 less deaths every year.

The goal of the study was to examine the risks and benefits to the health of regular bicycle riders of a sharing program. The researchers used nearly 182,000 participants of Barcelona’s share program, Bicing, and found that the benefits of reduced greenhouse gas emissions and increased physical activity far outweighed the risks of more exposure to traffic accidents and emissions from cars. The researchers compared a car driver’s risk to the same factors, and found that while cyclists did have a slightly increased risk of death from traffic incidents (mortality rate of 0.03) and air pollution (mortality rate of 0.13), the increased exercise accounted for 12.46 lives saved, making the total lives saved 12.28. On top of that, Bicing has reduced the region’s annual CO2 emissions by 9,000 metric tonnes.

A.K. Streeter at Treehugger explains that the researchers “took their data pool from only regular Bicing users, and assumed that 90% of them had only started regular cycle commuting after Bicing came into being.” Streeter adds that “the plus of this was that the study was able to measure differences more easily than if they had studied a group of regular commuter cyclists who simply joined Bicing when it started up instead of using their own bikes. The downside is that there’s no way to know if that assumption is accurate.”

While the study authors do concede that this research is limited because of the availability of data, its results are supported by several other studies that have shown similar benefits of public bike sharing programs. And really, any data that encourages or supports bike sharing programs is highly beneficial to the greater sustainable cause. Hopefully these studies will have an impact in America, where many bike share programs (like New York City’s) have been slow to get off the ground.